His bout with melanoma after the 2000 campaign makes his health and his age election issues today. Why he's still at risk

Years after McCain's surgery to remove skin cancer and lymph nodes, his left cheek still bears a visible seam.

It was the size of a dime and as thick as a nickela discolored blotch on John McCain's left temple. He didn't pay it much mind during the heat of the 2000 Republican primary campaign. But after losing the nomination to George W. Bush, the Arizona Senator found himself with time to spare. So as Bush celebrated victory, McCain headed to the National Naval Medical Center in Bethesda, Md., to have the spot checked out.

Less than three weeks later, McCain endured 5½ hours of surgery to remove a patch of skin including the blemish, roughly...